Multiple rotary engine

ABSTRACT

A pair of rotors of bulging triangular shape fit within a rectangular shaped interior portion of an engine casing, the rotors rotating in opposite directions and in peripheral contact with each other and the upper and lower and left and right side walls of the rectangular interior. As the rotors rotate, variable volumes between the rotor peripheries and the upper and lower and left and right walls are generated. By introducing an air-fuel mixture into the upper volume between peripheral portions of the rotors and the upper wall and igniting the mixture, the expanding gases drive the rotors in oppositely rotating directions thereby increasing the volume of the chamber to accommodate the expanding gases. As the upper volume is decreased the burnt gases are exhausted and on subsequent increase, a fresh air-fuel mixture is drawn into the volume and then compressed and the four cycles repeated. The arrangement is unique in that four cycles are completed within each two-thirds of a rotation of the rotors.

United States Patent Schubert Dec. 30, 1975 [54] MULTIPLE ROTARY ENGINE [57] ABSTRACT Inventor: Emil Georg Schuben, Kenyon A pair of rotors of bulging triangular shape fit within a -7 Los Angeles Cahf- 90066 rectangular shaped interior portion of an engine cas- [22] Filed; 2, 1974 ing, the rotors rotating in opposite directions and in peripheral contact with each other and the upper and PP 528,635 lower and left and right side walls of the rectangular interior. As the rotors rotate, variable volumes be- 52 U.S.C1. 123/8.47; 418/58; 418/113 tween the rotor peripheries and the pp and lower 51 Int. (:1. F0213 55/14; F01C 1/02 and left and right Wells are generated y introducing [58] Field of Search 123/847; 418/58, 113, an air-fuel mixture into the PP volume between P 418/204 ripheral portions of the rotors and the upper wall and I igniting the mixture, the expanding gases drive the ro- 5 References Cited tors in oppositely rotating directions thereby increas- UNITED STATES PATENTS ing the volume of the chamber to accommodate the 298 952 5/1884 D k, 418/58 expanding gases. As the upper volume is decreased m the burnt gases are exhausted and on subsequent ing grssi z 34 23 crease, a fresh air-fuel mixture is drawn into the vol- 3439654 4/1969 Campbell 123/847 ume and then compressed and the four cycles re- 3:7O9:199 1/1973 Molyneaux 123/847 peated. The arrangement is unique in that four cycles 3,726,617 4 1973 Daido 418/204 are completed wi hin ea h tw hir s of a rotation of FOREIGN PATENTS OR APPLICATIONS the 1,314,527 12/1962 France 123/8.47 1,326,623 4/1963 France 123/847 Primary ExaminerJohn J. Vrablik 20 Claims, 15 Drawing Figures Attorney, Agent, or FirmRalph B. Pastoriza L L l /Y T I ,1

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US. Patent Dec. 30, 1975 Sheet30f4 3,929,402

US. Patent Dec. 30, 1975 Sheet 4 of4 3,929,402

MULTIPLE ROTARY ENGINE This invention relates to internal combustion engines and more particularly to an improved multiple rotarytype internal combustion engine.

BACKGROUND OF THE INVENTION As is well known, experimentation with rotary engines started about the turn of the century and in fact some of these engines were actually built. Unfortunately, the engines that were fabricated did not realize the expectations and are, nowadays, hardly known. The aspired. goal was to change the force of expanding gases into rotation directly; that is, without reciprocating type pistons.

Eventually, an acceptable solution was accomplished with the invention of the Wankel engine employing a rotary disc. However, there is still room for substantial improvements particularly in the areas of fuel and oil consumption, proper sealing of the peripheral portions of the rotor, suitable isolation between the inlet and exhaust ducts to avoid escape of unburnt mixtures and a relatively low compression ratio, the latter factor preventing effective operation of the engine as a diesel engine.

BRIEF DESCRIPTION OF THE PRESENT INVENTION Briefly, the present invention contemplates a multiple rotary engine; that is, the use of more than one rotor. Essentially, the engine includes a casing having a rectangular interior incorporating left and right rotors in side-by-side relationship, the length of the interior being twice its width and each of the rotors having peripheries defined by three equal arcs of radius of curvature equal to the width so that they are always in physical contact with each other and the walls of the rectangular interior.

Inter-engaging means couple the rotors together for simultaneous rotation in opposite directions, rotation of the rotors defining with their peripheries and the central portion of one of the long walls of the rectangular interior a variable volume. Suitable inlet and exhaust valves communicate with this volume and are operated in conjunction with means for introducing an air-fuel mixture into the volume through the inlet valve when this volume is minimum in size.

Ignition of the air-fuel mixture in the minimum volume generates expanding gases which increase the volume by driving the rotors in opposite directions. Subsequent decrease of the volume upon further rotation of the rotors exhausts the burnt gases through the exhaust valve and still further rotation increases the volume to suck in a fresh supply of the air-fuel mixture. This fresh supply is then compressed and the four cycles repeated, each four cycles taking place during only two-thirds of a rotation of each of the rotors.

A further important feature of the invention includes the provision of an air chamber connected with the other variable volumes at the corners of the rectangular interior for taking advantage of the change in these volumes to provide compressed air for feeding into the one volume where combustion takes place. This super charging along with the specific design of the rotors provides an engine with a compression retio in excess of 8 to I and can be as high as 20:1 so that the same can readily be operated as a diesel engine.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing as well as many other features and advantages of the present invention will be had by now referring to the accompanying drawings in which:

FIG. 1 is a perspective view of the multiple rotary engine of this invention;

FIG. 2 is a cross section taken in the direction of the arrows 2-2 of FIG. 1;

FIG. 3 is a geometrical diagram illustrating the manner in which each of the rotors is designed;

FIG. 4 schematically illustrates a series of successive positions of the engine rotors including a complete four cycle operation;

FIG. 5 is a cross section of tghe multiple rotary engine wherein two additional rotors have been added;

FIG. 6 is a series of diagramatic illustrations showing one means of coupling one of the rotors to the drive shaft;

FIG. 7 is a series of diagramatic illustrations similar to FIG. 6 showing an alternative means of coupling the rotor to the drive shaft;

FIG. 8 is a still further diagramatic illustration of a modification of the coupling means of FIG. 7;

FIG. 9 is a fragmentary cross section taken in the direction of the arrows 99 of FIG. 8;

FIG. 10 is a fragmentary plan view of a peripheral portion of one of the rotors taken in the direction of the arrows 10-10 of FIG. 2;

FIG. 1 l is a fragmentary cross section in the direction of the arrows 11-11 of FIG. 10;

FIG. 12 is a view similar to FIG. 10 showing a modified arrangement of the rotor periphery;

FIG. 13 is a fragmentary elevational view taken in the direction of the arrows 13-l3 of FIG. 12;

FIG. 14 is a fragmentary plan view of an alternative design for the rotor periphery; and,

FIG. 15 is a fragmentary cross section taken in the direction of the arrows 15-15 of FIG. 14.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG. 1, the multiple rotary engine includes a casing 10 provided with front and rear cover plates 11 and 12 spaced a distance apart to define a depth D of the interior portion of the casing. As will become clearer with reference to FIG. 2, the casing defines a rectangular interior within which left and right rotors are positioned coupled to shafts l3 and 14. The shaft 13 is shown elongated to protrude from the rear cover 12 of the casing and in the embodiment shown, constitutes a drive shaft from which power from the engine may be taken.

Shown above the casing 10 is equalizer valve 15 to an interior air chamber 16. An exhaust valve 17 within a passage extending through and isolated from the air chamber 16 is also shown in the cut away portion. A further inlet valve within the air chamber 16 below equalizer valve 15 is provided and this valve together with the exhaust valve 17 is positively controlled by suitable mechanical connections designated schematically by the dash lines 18 in accord with the position of the rotor shaft 13.

Also shown in FIG. 1 are air inlet passages at the four corners of the casing such as indicated at 19, 20, 21 and 22. The air chamber 16 itself is provided with a safety valve 23.

Cooling water for the engine of FIG. 1 may be passed into suitable ports in the base of the casing and with- 3 drawn through upper spaced outlet ports as indicated.

Referring now to FIG. 2, details of the internal construction of the engine within the casing will be evident. As shown, the casing includes upper and lower walls 24 and 25 and left and right side walls 26 and 27 defining a hollow rectangular shaped interior 28 of given length L and given width W as designated at the top and side of the drawing of FIG. 2. As already mentioned in conjunction with FIG. 1, the depth of the rectangular interior 28 is shown as D. The length L is equal to twice the width W so that left and right half portions of the rectangular interior are square.

The left and right rotors coupled to the shafts 13 and 14 mentioned in FIG. 1 are shown in FIG. 2 at 29 and 30. The peripheries of each of these rotors are so defined that there is always a physical contact between portions of the rotor peripheries with each other and always a physical contact between the left rotor 29 with portions of the left side wall and upper and lower walls, and always a physical contact between the right rotor 30 and portions of the right side wall and upper and lower walls.

Inter-engaging means are provided for coupling the left and right rotors 29 and 30 together for simultaneous rotation in opposite directions. In the embodiment illustrated in FIG. 2, this inter-engaging means takes the form of gear teeth such as shown at 31 on the periphery of the right rotor 30.

Referring to the upper central portion of FIG. 2, the inlet valve disposed below the air chamber inlet valve is shown at 32 and is hereafter referred to as an upper inlet valve, the corresponding exhaust valve 17 described in FIG. 1 being indicated by the dotted lines which, it is understood, is behind the inlet valve 32 and thus not clearly visible in FIG. 2. Both the upper inlet valve 32 and upper exhaust valve 17 are disposed in the upper wall 24 midway of its length and communicate with an upper volume designated UV defined between portions of the peripheries of the rotors and the upper wall 24.

Referring to the lower central portion of the casing of FIG. 2, there are also provided a lower inlet valve 33 and a lower exhaust valve designated by the dotted lines 34 again positioned behind the valve 33. Both of these lower inlet and exhaust valves communicate with a lower volume defined between peripheral portions of the rotors and the lower wall 25, this latter volume being designated LV. It will be recalled from FIG. 1 that there were provided four air inlet passages 19, 20, 21 and 22. As shown in FIG. 2, these inlet passages at the corners of the casing communicate with corner volumes defined between the left and right rotors respectively and the left and right side walls and upper and lower walls of the rectangular interior. These corner volumes are designated CV. In addition to these inlet air passages, there are also provided at each of the four corners air outlet passages such as shown starting at the upper left hand corner at 35, 36, 37 and 38.

Each of the four air inlet passages 19 through 22 include aone-way check valve, the same being schematically illustrated by the ball and valve seat 39 in the air inlet passage 19. The check valves are oriented to permit air to pass through the air inlet passage to the corner volume but block air from passing out these inlet passages to the exterior from the corner volume.

Also provided are check valves for the outlet passages 35 through 38 such as schematically illustrated by the ball and valve seat 40 in passage 35 passing into passage 41 to chamber 16. It will be noted that the air passage 41 communicates with the air outlet passages 35 and 36 communicating with the upper and lower left side corners while an additional air passage 42 to the right of the casing communicates with the air passages 37 and 38 through the check valves in these passages and also with air chamber 16. The latter check valves are oriented to permit air to pass from the corner volumes through the passages 41 and 42 into the air chamber 16 and block air from the air chamber 16 from passing back into the corner volumes through these passages.

In addition to the air passages 41 and 42 surrounding the walls of the rectangular interior, there is interposed a water passage designated to the left of FIG. 2 at 43 which surrounds the upper and lower and left and right side walls of the rectangular interior. In fact, it will be noted that the upper and lower and left and right side walls of the rectangular interior form a common wall with the water passage 43. This passage communicates with the inlet and outlet ports in the base and top for the water as indicated by the arrows and provides for circulation of cooling water to keep the engine cool.

Referring once again to the upper central portion of FIG. 2, there is provided a fuel line 44 projecting into the area of the upper volume UV adjacent to the upper inlet valve 32. It should be understood that when the valve 32 opens and fuel is ejected from the fuel line 44, an air-fuel mixture is provided which is passed into the upper volume UV.- The inlet valve 32 and fuel line 44 have simply been illustrated schematically. An injection jet would ordinarily be utilized at this point.

Also schematically indicated immediately beneath the inlet valve 32 is a spark plug 45 and also a glow plug 46. Because of the high compression ratio capable of being developed by the engine of this invention, the same may operate as a diesel engine and instead of spark plug 45 an injection set is installed.

A similar fuel inlet line, spark plug, and glow plug are shown at 47, 48 and 49 respectively in the lower central portion cooperating with the lower inlet valve 33.

It will be appreciated from the description thus far, that if the left and right rotors 29 and 30 rotate in opposite directions as indicated by the arrows, the various upper. and lower volumes UV and LV and the corner volumes CV will all cyclically vary between minimum and maximum values. The motion of each of the rotors, however, is not about a single axis but rather about an axis which in turn revolves about the geometrical center of each half portion of the rectangular interior. In order to couple this motion to the output shaft such as the shaft 13 for the left rotor 29, the rotor is provided with a central bore 50 of a given diameter. This bore 50 has its axis coincident with the geometric center of the rotor 29 which axis is displaced from the geometric center of the square half portion of the rectangular interior. This latter geometric center coincides with the axis of the shaft 13. The shaft 13 is of lesser diameter than the bore 50 and passes through the bore with a peripheral portion in tangential relationship to the inside surface of the bore. Coupling is provided by internal gear teeth 51 in the bore 50 and external gear teeth 52 of the shaft 13.

All of the foregoing will become clearer by now referring to FIG. 3 illustrating the manner in which each of the rotors is designed.

In this design, a square is constructed of side a which corresponds in area precisely to one half the area of the left sides of the square at the points P2 and P3.

From the intersection point P2 a second arc A2 is swung of the same radius of curvature and similarly from the point P3 a third are A3 is swung of the same I radius of curvature. The resulting geometric configuration within the square defines the periphery of the rotor. In other words, the periphery of each rotor is defined by three circular arcs of equal length, each of radius of curvature equal to the given width of the rectangular interior. I

If the radii of each arc is drawn from the points P1, P2, and P3 to the mid points of the arcs as shownin FIG. 3, their common intersection point Cl constitutes the geometric center of the rotor. The geometric center of the square of side a, on the other hand, is located at C2 which is displaced from C1.

When the rotor as described in FIG. 3 rotates within the confines of the square, the geometric center C2 of the square. The translation of this motion to the shaft 13 will be further described subsequently.

FOUR CYCLE OPERATION Referring now to FIG. 4, there is set forth a series of schematic diagrams of successive positions of the left and right rotors 29 and 30 useful in explaining the operation of the engine shown in FIG. 2. I

The first diagram A shows the rotors during the end portion of an exhaust cycle, the upper center arrow indicating the exhaust gases and the lower center arrow indicating incoming air as this lower volume increases.

The next diagram B below the dashed line 53 shows the rotors in first positions which for purposes of thepresent description starts the four cycle operation. In the positions of diagram B, the upper volume is minimum and continued rotation of the rotors 29 and 30 in the directions indicated by the arrows towards second position results in this upper volume increasing towards. a maximum. Diagram C shows an intermediate position between the first and second positions and diagram D shows the second positions wherein the upper volume UV is maximum. These described movements between the first and second positions define an intake cycle.

In moving from the second position shown in diagram D towards third positions as indicated in diagrams E and F, a compression of the upper volume UV takes place, both inlet and exhaust valves being closed. These movements define a compression cycle and in the final third positions illustrated in diagram F, the upper vol ume is again minimized and ignition of the air-fuel mixture takes place at this point.

The expanding combustion gases then drive the rotors from the third positions of diagram F through the intermediate position of diagram G to fourth positions illustrated in diagram l-l. These movements define the combustion cycle. When the rotors reach the fourth positions illustrated in diagram H, the exhaust valve for the upper volume is opened as indicated by the center arrow preparatory to exhausting the gases under continued rotation of the rotors. Thus, as indicated in diagram l, the burnt gasesare being expelled by continued movement of the rotors after their fourth positions in diagram H. These motions complete the exhaust cycle 6 and when the rotors reach the positions illustrated in diagram J a new set of four cycles starts.

The start of the four cycles is represented by the dashed line 54, the positions of the rotors in diagram J corresponding to the first positions of the rotors described in diagram B. 4

It will be noted that while the positions of the rotors in diagram J define a minimum volume for the upper volume preparatoryto an intake of a fresh air-fuel mixture, they are not really physically in the identical positions as they were in diagram B. Rather, each of the rotors has only executed a two-thirds rotation during the four cycle operation as will be evident by tracing the successive positions of the rotors in diagrams B through I. Actually, the rotors must continue to rotate an additional or one third revolution to regain their initial first positions as will be evidenced by following the diagrams- K, L and the first diagram A.

The above described four cycle operation utilizing only two-thirds of a rotation for each rotor constitutes an important feature of this invention in that the actual peripheral portions of the rotors defining the combustion chamber during the combustion cycle successively shift between various thirds of the peripheries.

For example, and with reference to FIG. 4 it will be evident that when the four cycles start over again with diagram J, and air-fuel mixture is drawn into the upper volume as indicated by the upper arrows in diagrams J and K as this volume increases. In the second postions of diagram L and upon continued movement towards the third postions, the compression cycle takes place so that the starting at the left top, the diagram A will be representing completion of the compression cycle rather than an exhaust cycle and diagram B will be representing the point of ignition and diagrams C and D will be representing the combustion cycle rather than the intake cycle. It will be evident that different peripheral thirds of the rotors define the combustion chamber in this latter cycle as compared to the first mentioned combustion cycle.

The beneficial result of the foregoing is that the rotors are maintained relatively cool since combustion only affects one third of their peripheries at a time,

these peripheries havingan opportunity to be cooled as they rotate towards the side walls.

In the various cycle diagrams of FIG. 4, there are shown at the corners of the diagrams, arrows indicating when air is being drawn into the corner volumes CV and when air is beingpushed out of these corner volumes.

It will be evident that during the various positions in the cycles, the corner volumes alternately draw in air and expel air. Because of the check valve arrangements in the air inlet and outlet passages described in conjunction with FIG. 2, the air which is expelled from the corner volumes such as is occurring in diagrams B, E, l

and J is forced into the passages 41 and 42 of FIG. 2 through the check valves in these passages such as the check valve 40 to the air chamber 16 providing compressed air in this chamber. This highly compressed air mixes with the fuel at the time the inlet valve is opened to admit the air and, during the inlet cycle, or when diesel fuel is used, at the end of the compression cycle, theintroduced air is already under a high pressure from the air chamber 16. The air drawn into the corner volumes cools the rotors and walls of the casing before it is compressed in'the chamber 16.

7 The corner volumes are thus utilized to provide'a cooling and super charger type operation for the engine.

DOUBLE COMBUSTION OPERATION It will be recalled in FIG. 2 that there was described in the lower central portion lower inlet and exhaust valves. Referring once again to FIG. 2, it will be noted that the inlet valve 33 communicates with the air passages 41 and 42 which in turn communicate with the air chamber 16.

If desired, the lower volume LV can also be utilized as a combustion chamber in the same manner as the upper volume UV but wherein the ignition takes place at a different time to assure that the rotors will continue to rotate in the same direction.

More particularly, and with reference once again to FIG. 4, whenever the rotors are moving from positions slightly following the second position, shown in diagram D towards the third position in diagram F wherein the lower volume is increasing, an air-fuel mixture is introduced into the lower volume and ignited. This combusting air-fuel mixture can be visualized in the lower volume in diagram E as expanding to further drive the rotors to the position illustrated in diagram F.

Exhaust of the burnt gases in the lower volume would occur during the combustion cycle of the upper volume as indicated in diagrams G and H.

As in the case of the four cycle operation described in conjunction with the upper volume, compressed air fuel mixtures would be introduced into the lower volume under high pressure from the air chamber 16. Substantially greater power can thus be provided as a consequence of the double combustion action described.

Referring now to FIG. 5, there is shown a modification of the basic structure wherein additional rotors are provided. Essentially, an additional casing structure 55 containing additional left and right rotors 56 and 57 constructedidentically tothe first mentioned casing and left and right rotors is inverted and secured on top of the first mentioned casing containing the rotors 29 and 30, the upper volume defined by the rotors 29 and 30 being in communication with the corresponding upper volume of the additional casing structure which assumes a lower position upon inverting of the casing structure, all as shown in FIG. 5. It will be appreciated that in this inversion process, the additional left rotor 56 assumes a right hand position as viewed in FIG. 5 and the additional right rotor 57 assumes a left hand position.

It will further be understood in conjunction with FIG. 5 that the common combustion chamber for all four rotors shown at 60 in the central portion of the drawing is provided with an inlet and exhaust valve which may feed through the front and rear cover plates, these inlet and exhaust valves and passages being schematically indicated by the dashed lines 58 and 59 respectively. Further, a pre-compression air chamber corresponding to the air chamber 16 would be provided in communication with the inlet valve either on the front or rear of the overall casing structure. To provide a common power output shaft, one of the shafts for the additional rotors such as for the rotor 57 would be directly coupled to the shaft for the rotor 29 as indicated by the dashed line 61 in FIG. 5.

As shown by the arrows in FIG. 5, all four rotors are driven simultaneously when combustion takes place in the common combustion chamber 60, the expanding gases exerting pressure in all directions since the volume increases in all directions.

The additional rotors 56 and 57 execute a four cycle operation every two-thirds of a rotation in an identical manner to that described for the rotors 29 and 30 in conjunction with FIG. 2 and thus further description of the embodiment of FIG. 5 is not believed necessary.

FIG. 6 illustrates by a series of diagrams schematically depicting the left half of the rectangular interior 28 of FIG. 2, successive relative positions of the rotor 29 during a 60 rotation. Thus as the rotor moves from the position shown in diagram I in FIG. 6 to the position shown in diagram II the shaft 13 executes a 90 turn rotating in the same direction as the rotor. In moving from the position shown in diagram II to the position shown in diagram III, the shaft 13 again executes a 90 rotation. Thus for each 60 actual rotation of the rotor 29, the shaft 13 will be rotated 180 and for a twothirds rotation of the rotor to complete a four cycle operation, the shaft 13 will be driven by the intermeshing gear arrangement through two complete rotations.

FIG. 7 illustrates a further set of three diagrams showing successive positions of a modified rotor 62 wherein coupling to a shaft is accomplished by providing the rotor 62 with a central bore coaxial with its geometric center as described in conjunction with FIG. 3 having three circumferentially spaced cavities 64, 65 and 66.

The shaft for the rotor 62 is shown at 67 and has an outside diameter less than the given diameter of the bore so that the shaft passes through the bore. As in the case of FIG. 6, the axis of the shaft is coaxial with the geometrical center of the square interior portion constituting half of the rectangular portion of the casing. This shaft, as shown, includes at least one pair of diametrically opposite lobes 68 and 69, a lobe on the shaft being received in a juxtaposed cavity so that rotation of the rotor rotates the shaft in the same direction as will be evident from the successive diagrams II and III.

FIG. 8 and 9 illustrate a further modification of the coupling between the rotor and a shaft wherein in FIG. 8 the modified rotor is shown at 70 and shaft at 71. In this embodiment, the shaft includes in addition to a first pair of diametrically opposite lobes 72, second and third pairs of diametrically opposite lobes 73 and 74 axially spaced from the first pair and successively rotated 60 from the lobes of the first pair.

The bore in the rotor, in turn, includes a first set of three cavities one of which is indicated at 75 and second and third sets of three cavities, one in each of these latter sets being designated 76 and 77, the second and third sets being successively rotated 40 from the first set of cavities.

The foregoing arrangement will be better understood by referring to the cross section of FIG. 9 which clearly shows the diametrically opposite pairs of lobes 72, 73 and 74 positioned to cooperate with the three sets of axially spaced cavities.

It will be understood that the lobes from the three pairs will be received in cavities in the three sets when particular embodiment shown in FIG. 2, the gear teeth extend from the front to the rear end of the rotor; that is, over the distance D or depth of the rectangular interior and the rotor itself.

In order to improve sealing between the teeth and the upper and lower and side walls of the interior of the casing, each of the gear teeth includes a resilient seal biased radially outwardly from its tip. Referring to FIG. 11, this seal takes the form of an inverted T-shaped member 78 in an inverted T-shaped cavity 79 in each tooth 31. A small leaf spring 80 is positioned beneath the member 78 to bias the tip of the T in a radially outward direction from the top of the tooth 31. This tip may include a seal 81 which will be in pressing engagement with the rectangular interior wall portions of the casing as the rotor rotates, and thus a highly improved sealing of the rotor against the walls is accomplished.

FIG. 12 illustrates a modification of the tooth structure shown in FIG. wherein the gear teeth 31 are arranged in three circumferential side-by-side rows 82, 83 and 84 staggered with respect to each other to minimize leakage paths from the front of each of the gear teeth to the rear of each of the gear teeth and prevent vibration. FIG. 13 shows in fragmentary elevation, the appearance of these teeth looking in the direction of the arrows l3l3 of FIG. 12. v

Rather than actual gear teeth, the inter-engaging means coupling the left and right rotors together may comprise rollers on the peripheries of the rotors which inter-engage with each other at the points of physical contact of the rotors with each other in the manner of gear teeth.

FIG. 14 shows the foregoing arrangement wherein there are provided rollers arranged in three circumferential side-by-side rows staggered with respect to each other to again minimize leakage. These rollers are shown at 85, 86 and 87. Further inhibition of leakage between the rollers is accomplished by providing circumferential sealing rings for the outer rows and between the rows such as indicated at 88, 89, 90 and 91.

Referring to the cross section of FIG. 15, one of these circumferential sealing rings 90 is shown exploded away from the rollers 85, 86 and 87 and it will be noted that the upper arc defining the sealing ring 90 when the sealing ring is in position falls below the topmost portions of the rollers so that inter-engagement of the rollers on the various rotors can operate in the manner of gear teeth to couple the rotors together.

To help assure that the rollers stay in pressure-rolling contact with the upper and lower and left and right side walls of the rectangular interior, the invention contemplates in embodiments utilizing the rollers the provision of thin steel plates lining the upper and lower and left and right walls. Referring to FIG. 2, these thin steel plates are shown forming the upper and lower walls 24 and 25 and lining the left and right side walls 26 and 27. The steel plates are arranged to be bowed inwardly slightly so that a spring" pressure is exerted against efficiency is realized from the design as described together with the provision of a relatively high compression ratio resulting from the unique pre-compression of air by different peripheral portions of the rotors. As a consequence, the engine can operate as a gasoline engine or as a diesel engine all as described herein, or one combustion chamber can be used for gasoline and the other for diesel fuel, so that simultaneously, different fuels can be used to drive the engine.

What is claimed is:

1. A multiple rotary internal combustion engine comprising, in combination:

a. a casing having a rectangular interior incorporating left and right rotors in side-by-side relationship, the length of the interior being twice its width and each of the rotors having peripheries defined by three equal arcs of radius of curvature equal to said width so that they are always in physical contact with each other and the walls of the rectangular interior;

b. inter-engaging means coupling said rotors rogether for simultaneous rotation in opposite directions, rotation of said rotors defining with their peripheries and the central portion of one of the long walls of the rectangular interior, a variable volume;

' c. inlet and exhaust valves connecting with said variable volume;

d. means for introducing an air-fuel mixture into said volume through said inlet valve when minimum in size; and,

e. means for igniting said air-fuel mixture, said inlet and exhaust valves operating in response to given rotor positions to provide a four-cycle engine operation for every two-thirds rotation of the rotors.

2. An engine according to claim 1, in which variable corner volumes are defined between the peripheral portions of the rotors and corners of the interior and include air inlet and air outlet passages, the outlet passages passing air compressed in said corner volumes to said inlet valve to provide a super charger operation for said engine, the inlet air cooling the rotors and walls.

3. An engine according to claim 1, including an additional casing with additional rotors all identical to said first mentioned casing and rotors, secured to the first mentioned casing in inverted relationship so that its variable volume is in communication with the first mentioned variable volume to define a common combustion volume for all four rotors.

4. A multiple rotary internal combustion engine comprising, in combination:

a. an engine casing having upper and lower walls and left and right side walls defining a hollow rectangular shaped interior of given length and given width, said casing further including front and rear cover plates defining therebetween a given depth of said interior, the length of the interior being equal to twice the widthof the interior;

b. left and right rotors of thickness corresponding substantially to said given depth positionedin sideby-side relationship in said rectangular interior, the periphery of each rotor being defined by three circular arcs of equal length each of radius of curvature equal to said given width of the rectangular interior such that there is always a physical contact between portions of the rotor peripheries with each other and always a physical contact between the left rotor with portions of the left side wall and upper and lower walls and always a physical 1 1 contact between the right rotor with portions of the right side wall and upper and lower walls;

c. inter-engaging means coupling said left and right rotors for simultaneous rotation in opposite directions;

d. an output shaft coupled to said left rotor for rotation thereby;

e. upper inlet and exhaust valves in the upper wall midway of its length communicating with an upper volume defined between peripheral portions of the rotors and the upper walls;

. lower inlet and outlet passages in the lower wall midway of its length communicating with a lower volume defined between peripheral portions of the rotors and the lower wall;

air inlet and air outlet passages at each of the four corners of the rectangular interior;

h. coupling means between said output shaft and said upper inlet and exhaust valves for opening and closing said valves in response to given rotative positions of the rotors;

. means for supplying an air-fuel mixture to said inlet valve; and,

j. means in said upper volume for igniting said air-fuel mixture in said volume,

whereby when said rotors move from first positions in which said upper volume is minimum to second positions in which said upper volume is maximum, said upper inlet valve is opened so that said air-fuel mixture is drawn into said volume to define a first inlet cycle, said inlet valve closing when said rotors reach said second positions, continued rotation of said rotors from said second positions to third positions compressing said air-fuel mixture in said upper volume by decreasing the same to define a compression cycle, said air-fuel mixture being ignited when said rotors reach said third positions, the expanding combusting gases driving said rotors from said third positions to fourth positions in which said volume is again maximized to define a combustion cycle, said exhaust valve being opened when said rotors are in said fourth positions, continued rotations of said rotors from said fourth positions decreasing said upper volume to expel burnt gases through said exhaust valve to define an exhaust cycle, said rotors having then completed a two-thirds rotation each during which the four cycles of operation are carried out at which point they are in a position corresponding to said first position in that said upper volume is again a minimum and increases under further rotation of said rotors, the inlet valve being opened to permit intakeof a new air-fuel mixture thus starting the four cycles over again, different peripheral thirds of the rotors defining the upper volume during combustion thereby being successively utilized during each combustion cycle.

5. An engine according to claim 4, in which said casing defines an air chamber communicating with said inlet valve, the outlet passages at the corners of said rectangular interior communicating with said air chamber through check valves which pass air into said chamber from said passages and block air in said chamber from passing back through said outlet passages, said inlet passages at the corners of said rectangular interior communicating with the exterior through check valves which permit air to pass into the corner volumes of the rectangular interior and block air from passing out to the exterior, whereby air is drawn through the inlet passages into the respective corner volumes defined between peripheral portions of the rotors and the left and right side walls and upper and lower walls, when said corner volumes are increasing as a consequence of rotation of said rotors, and forced into said air chamber through said outlet passages when said corner volumes are decreasing so that the air-fuel mixture passed through said inlet valve is super charged, the compression ratio of said engine being greater than 8 to l.

6. An engine according to claim 4, in which said ignition means comprises a spark plug.

7. An engine according to claim 4, in which said ignition means comprises a glow plug, fuel being injected and ignited to operate as a diesel engine.

8. An engine according to claim 4, in which said lower inlet and outlet passages in the lower volume defined between peripheral portions of the rotors and said lower wall include lower inlet and exhaust valves; means for introducing an air-fuel mixture through said lower inlet valve; and means for igniting said air-fuel mixture so that combustion takes place to exert further driving forces on said rotors whenever said rotors are moving'from positions slightly following said second position towards said third position wherein said lower volume is increasing to thereby provide a double acting multiple rotary engine.

9. An engine according to claim 4, including an additional casing structure containing additional left and. right rotors constructed identically to said first mentioned casing and left and right rotors, said additional casing being inverted and secured on top of said first mentioned casing, the upper volume in said first mentioned casing being in communication with the corresponding upper volume of said additional casing structure which assumes a lower position upon inverting of said additional casing structure, whereby all four rotors are driven simultaneously during said combustion cycle, the expanding gases increasing the volume in all directions; and, means coupling the additional rotors to said drive shaft.

10. An engine according to claim 4, in which said casing includes a water passage having a common wall with the said upper and lower walls and left and right side walls for circulating water to cool the walls.

11. An engine according to claim 4, including gear means coupling said ouput shaft to said left rotor, said gear means including inner gear teeth formed on the inner circumference of a bore of given diameter passing through the geometrical center of said rotor, and outer gear teeth formed on the outside of said shaft, said shaft having an outside diameter less than said given diameter so that the shaft passes through said bore, the axis of the shaft passing through the geometrical center of the square interior portion within which the rotor is positioned making up one half of said rectangular interior, the outer gear teeth on said shaft meshing with said inner gear teeth so that rotation of said rotor rotates said shaft in the same direction.

12. An engine according to claim 4, including a bore of given diameter through the geometrical center of said left rotor, said shaft having an outside diameter of less than said given diameter so that the shaft passes through said bore, said shaft having at least one pair of diametrically opposite lobes, the axis of the shaft passing through the geometrical center of the square interior portion within which said rotor is positioned making up one half of said rectangular interior, said bore having one set of three equally circumferentially spaced cavities, a lobe on said shaft being received in a juxtaposed cavity, so that rotation of said rotor rotates said shaft in the same direction.

13. An engine according to claim 12, in which said shaft includes second and third pairs of diametrically opposite lobes axially spaced from said one pair and successively rotated 60 from the lobes of said one pair, said bore including second and third sets of three equally circumferentially spaced cavities, successively rotated 40 from said one set of cavities, lobes from the second and third pairs being received in cavities of the second and third sets when juxtaposed thereto so that a more uniform driving coupling is provided between said rotor and shaft.

14. An engine according to claim 4, in which said inter-engaging means coupling said left and right rotors together comprises intermeshing gear teeth on the peripheries of said rotors. I

15. An engine according to claim 14, in which said gear teeth are arranged in three circumferential sideby-side rows staggered with respect to each other to minimize leakage.

16. An engine according to claim 14, in which each of said gear teeth includes a resilient seal biased radially outwardly from its tip.

17. An engine according to claim 4, in which said inter-engaging means coupling said left and right rotors together comprises rollers on the peripheries of said rotors which inter-engage with each other at the points of physical contact of the rotors with each other in the manner of gear teeth.

18. An engine according to claim 17, in which said upper and lower walls and left and right side walls are lined with steel which is biased inwardly slightly to provide a pressure against the rollers on the peripheral portions of said rotors in physical contact therewith.

19. An engine according to claim 17, in which said rollers are arranged in three circumferential side-byside rows staggered with respect to each other to prevent leakage and vibration of the rotors.

20. An engine according to claim 19, including circumferential sealing rings between said rows of rollers and at the front and rear of the rotor. 

1. A MULTIPLE ROTARY INTERNAL COMBUSTION ENGINE COMPRISING, IN COMBINATION: A. A CASING HAVING A RECTANGULAR INTERIOR INCORPORATING LEFT AND RIGHT ROTORS IN SIDE-BY-SIDE RELATIONSHIP, THE LENGTH OF THE INTERIOR BEING TWICE ITS WIDTH AND EACH OF THE ROTORS HAVING PERIPHERIES DEFINED BY THREE EQUAL ARCS OF RADIUS OF CURVATURE EQUAL TO SAID WIDTH SO THAT THEY ARE ALWAYS IN PHYSICAL CONTACT WITH EACH OTHER AND THE WALLS OF THE RECTANGULAR INTERIOR; B. INTER-ENGAGING MEANS COUPLING SAID ROTORS TOGETHER FOR SIMULTANEOUS ROTATION IN OPPOSITE DIRECTIONS, ROTATION OF SAID ROTORS DEFINING WITH THEIR PERIPHERIES AND THE CENTRAL PORTION OF ONE OF TH LONG WALLS OF THE RECTANGULAR INTERIOR, A VARIABLE VOLUME; C. INLET AND EXHAUST VALVES CONNECTING WITH SAID VARIABLE VOLUME; D. MEANS FOR INTRODUCING AN AIR-FUEL MIXTURE INTO SAID VOLUME THROUGH SAID INLET VALVE WHEN MINIMUM IN SIZE; AND, E. MEANS FOR IGNITING SAID AIR-FUEL MIXTURE, SAID INLET AND EXHAUST VALVES OPERATING IN RESPONSE TO GIVEN ROTOR POSITIONS TO PROVIDE A FOUR-CYCLE ENGINE OPERATION FOR EVERY TWO-THIRDS ROTATION OF THE ROTORS.
 2. An engine according to claim 1, in which variable corner volumes are defined between the peripheral portions of the rotors and corners of the interior and include air inlet and air outlet passages, the outlet passages passing air compressed in said corner volumes to said inlet valve to provide a super charger operation for said engine, the inlet air cooling the rotors and walls.
 3. An engine according to claim 1, including an additional casing with additional rotors all identical to said first mentioned casing and rotors, secured to the first mentioned casing in inverted relationship so that its variable volume is in communication with the first mentioned variable volume to define a common combustion volume for all four rotors.
 4. A multiple rotary internal combustion engine comprising, in combination: a. an engine casing having upper and lower walls and left and right side walls defining a hollow rectangular shaped interior of given length and given width, said casing further including front and rear cover plates defining therebetween a given depth of said interior, the length of the interior being equal to twice the width of the interior; b. left and right rotors of thickness corresponding substantially to said given depth positioned in side-by-side relationship in said rectangular interior, the periphery of each rotor being defined by three circular arcs of equal length each of radius of curvature equal to said given width of the rectangular interior such that there is always a physical contact between portions of the rotor peripheries with each other and always a physical contact between the left rotor with portions of the left side wall and upper and lower walls and always a physical contact between the right rotor with portions of the right side wall and upper and lower walls; c. inter-engaging means coupling said left and right rotors for simultaneous rotation in opposite directions; d. an output shaft coupled to said left rotor for rotation thereby; e. upper inlet and exhaust valves in the upper wall midway of its length communicating with an upper volume defined between peripheral portions of the rotors and the upper walls; f. lower inlet and outlet passages in the lower wall midway of its length communicating with a lower volume defined between peripheral portions of the rotors and the lower wall; g. air inlet and air outlet passages at each of the four corners of the rectangular interior; h. coupling means between said output shaft and said upper inlet and exhaust valves for opening and closing said valves in response to given rotative positions of the rotors; i. means for supplying an air-fuel mixture to said inlet valve; and, j. means in said upper volume for igniting said air-fuel mixture in said volume, whereby when said rotors move from first positions in which said upper volume is minimum to second positions in which said upper volume is maximum, said upper inlet valve is opened so that said air-fuel mixture is drawn into said volume to define a first inlet cycle, said inlet valve closing when said rotors reach said second positions, continued rotation of said rotors from said second positions to third positions compressing said air-fuel mixture in said upper volume by decreasing the same to define a compression cycle, said air-fuel mixture being ignited when said rotors reach said third positions, the expanding combusting gases driving said rotors from said third positions to fourth positions in which said volume is again maximized to define a combustion cycle, said exhaust valve being opened when said rotors are in said fourth positions, continued rotations of said rotors from said fourth positions decreasing said upper volume to expel burnt gases through said exhaust valve to define an exhaust cycle, said rotors having then completed a two-thirds rotation each during which the four cycles of operation are carried out at which point they are in a position corresponding to said first position in that said upper volume is again a minimum and increases under further rotation of said rotors, the inlet valve being opened to permit intake of a new air-fuel mixture thus starting the four cycles over again, different peripheral thirds of the rotors defining the upper volume during combustion thereby being successively utilized during each combustion cycle.
 5. An engine according to claim 4, in which said casing defines an air chamber communicating with said inlet valve, the outlet passages at the corners of said rectangular interior communicating with said air chamber through check valves which pass air into said chamber from said passages and block air in said chamber from passing back through said outlet passages, said inlet passages at the corners of said rectangular interior communicating with the exterior through check valves which permit air to pass into the corner volumes of the rectangular interior and block air from passing out to the exterior, whereby air is drawn through the inlet passages into the respective corner volumes defined between peripheral portions of the rotors and the left and right side walls and upper and lower walls, when said corner volumes are increasing as a consequence of rotation of said rotors, and forced into said air chamber through said outlet passages when said corner volumes are deCreasing so that the air-fuel mixture passed through said inlet valve is super charged, the compression ratio of said engine being greater than 8 to
 1. 6. An engine according to claim 4, in which said ignition means comprises a spark plug.
 7. An engine according to claim 4, in which said ignition means comprises a glow plug, fuel being injected and ignited to operate as a diesel engine.
 8. An engine according to claim 4, in which said lower inlet and outlet passages in the lower volume defined between peripheral portions of the rotors and said lower wall include lower inlet and exhaust valves; means for introducing an air-fuel mixture through said lower inlet valve; and means for igniting said air-fuel mixture so that combustion takes place to exert further driving forces on said rotors whenever said rotors are moving from positions slightly following said second position towards said third position wherein said lower volume is increasing to thereby provide a double acting multiple rotary engine.
 9. An engine according to claim 4, including an additional casing structure containing additional left and right rotors constructed identically to said first mentioned casing and left and right rotors, said additional casing being inverted and secured on top of said first mentioned casing, the upper volume in said first mentioned casing being in communication with the corresponding upper volume of said additional casing structure which assumes a lower position upon inverting of said additional casing structure, whereby all four rotors are driven simultaneously during said combustion cycle, the expanding gases increasing the volume in all directions; and, means coupling the additional rotors to said drive shaft.
 10. An engine according to claim 4, in which said casing includes a water passage having a common wall with the said upper and lower walls and left and right side walls for circulating water to cool the walls.
 11. An engine according to claim 4, including gear means coupling said ouput shaft to said left rotor, said gear means including inner gear teeth formed on the inner circumference of a bore of given diameter passing through the geometrical center of said rotor, and outer gear teeth formed on the outside of said shaft, said shaft having an outside diameter less than said given diameter so that the shaft passes through said bore, the axis of the shaft passing through the geometrical center of the square interior portion within which the rotor is positioned making up one half of said rectangular interior, the outer gear teeth on said shaft meshing with said inner gear teeth so that rotation of said rotor rotates said shaft in the same direction.
 12. An engine according to claim 4, including a bore of given diameter through the geometrical center of said left rotor, said shaft having an outside diameter of less than said given diameter so that the shaft passes through said bore, said shaft having at least one pair of diametrically opposite lobes, the axis of the shaft passing through the geometrical center of the square interior portion within which said rotor is positioned making up one half of said rectangular interior, said bore having one set of three equally circumferentially spaced cavities, a lobe on said shaft being received in a juxtaposed cavity, so that rotation of said rotor rotates said shaft in the same direction.
 13. An engine according to claim 12, in which said shaft includes second and third pairs of diametrically opposite lobes axially spaced from said one pair and successively rotated 60* from the lobes of said one pair, said bore including second and third sets of three equally circumferentially spaced cavities, successively rotated 40* from said one set of cavities, lobes from the second and third pairs being received in cavities of the second and third sets when juxtaposed thereto so that a more uniform driving coupling is provided between said rotor and shaft.
 14. An engine according to claim 4, in which said inter-engaging means coupling said left and right rotors together comprises intermeshing gear teeth on the peripheries of said rotors.
 15. An engine according to claim 14, in which said gear teeth are arranged in three circumferential side-by-side rows staggered with respect to each other to minimize leakage.
 16. An engine according to claim 14, in which each of said gear teeth includes a resilient seal biased radially outwardly from its tip.
 17. An engine according to claim 4, in which said inter-engaging means coupling said left and right rotors together comprises rollers on the peripheries of said rotors which inter-engage with each other at the points of physical contact of the rotors with each other in the manner of gear teeth.
 18. An engine according to claim 17, in which said upper and lower walls and left and right side walls are lined with steel which is biased inwardly slightly to provide a pressure against the rollers on the peripheral portions of said rotors in physical contact therewith.
 19. An engine according to claim 17, in which said rollers are arranged in three circumferential side-by-side rows staggered with respect to each other to prevent leakage and vibration of the rotors.
 20. An engine according to claim 19, including circumferential sealing rings between said rows of rollers and at the front and rear of the rotor. 